1. Area of the Art
The present invention relates to a device for providing a controlled gas fired flame for use in igniting flammable materials, particularly artificial or natural logs in a fireplace or charcoal or wood in a cooking fire or stove. More particularly, the invention relates to hand held devices which contain a fuel source, an igniter for the fuel, a delivery tube for presenting a flame at a distance spaced from the hand of the operator and various controls and safety devices to trigger the flame, control the size of the flame and prevent inadvertent ignition of the flame.
2. Description of the Prior Art
Numerous utility and design patents have issued covering various mechanical features of such devices, means for igniting the flammable gas contained therein, and numerous external, non-functional features. All of the relevant utility patents include a gas canister, a trigger and a wand. Some of the prior devices incorporate a trigger in the handle, the trigger activated in a manner similar to a gun, while others use a top mount trigger which is depressed into the device or slid along the top of the device to cause ignition. Most patents have means to ignite the gas and some have a valve to vary the gas flow rate.
U.S. Pat. Nos. 5,738,507 and 5,326,256 to Tokai show a linear body with a gun trigger. The trigger applies pressure directly to the valve opening mechanism on the fuel tank as well as to a piezoelectric igniter. Depressing the trigger causes the gas to be released and feed to a nozzle at the end of the wand and simultaneously activate the piezoelectric sending current to a discharge electrode also located at the end of the wand. A key feature of the '507 design is that the wand is flexible to aid in reaching into difficult locations.
U.S. Pat. No. 4,253,820 is to an igniter shaped like a pistol having a trigger switch to release the gas into the wand, the gas being ignited by a match placed at the end of the wand.
U.S. Pat. No. 3,947,731 is to a trigger activated igniter which includes a normally closed, spring loaded valve. Depressing the trigger pulls back the valve, compressing the spring allowing gas to flow. At the same time the spark is activated, igniting the gas.
U.S. Pat. No. 3,576,471 is a pistol shaped igniter with a trigger switch. Depression of the trigger opens the gas valve and cocks a striker hammer which in turn strikes a piezoelectric crystal creating a spark to ignite the gas.
U.S. Pat. No. 5,154,601 is to a liquefied gas igniter having a top mounted trigger. Sliding the trigger longitudinally forward opens the fuel container and activates the piezoelectric chip which is located in the delivery tube forward of the trigger.
U.S. Pat. No. 4,538,983 to Zeller includes a top mounted trigger which, when pressed moves into the body at a 90.degree. angle to the axis of the wand. Activation of the trigger causes a rotatable cam 27 to swing forward activating the piezoelectric mounted forward of the trigger and to rotate rocker lever 16,17, located rearward of the trigger to open the gas valve.
U.S. Pat. No. 4,516,933 is directed to an igniter with a top mounted switch where the improvement is a fuel reservoir which constitutes a major portion of the handle. There is no discussion of the functioning of the unit or the location or interaction of the various components.
The igniter of U.S. Pat. No. 4,292,021 has a top mounted, L-shaped trigger. When the exposed portion of the trigger is rotated rearwardly a lever, which constitutes the bottom half of the L-shaped trigger, rotates forward inside the body opening the gas valve and activating the piezoelectric chip causing a spark to be generated at the end of the wand where the gas outlet is located. A fuel control knob is exposed through the handle so that it can be operated by the same hand which also activates the trigger.
U.S. Pat. No. 4,273,528 is directed to a tubular igniter with a sliding trigger which can be operated either as a top mounted, thumb activated trigger or as a bottom mounted trigger operable by other fingers.
Surface mounted activation buttons, which could be depressed down into, or slid along, the surface of the handle are shown in U.S. Design Pat. Nos. D403,206, D382,444, D382,172, D380,936, D314,118, D295,598, D293,603, D277,307, D277,307, D267,820, D258,840, D254,872, D241,645 AND D231,119. Aside from showing a trigger mechanism which can be activated by movement of a users thumb, and various surface mounted switches of unknown utility theses design patents fail to show a mechanic structure that functions in the same way as applicant's invention.
Upon review of the products on the market it has become apparent that there is a need for an easily operated device which includes the ability to reach into enclosed spaces while at the same time having the flexibility of providing a variable sized flame, an ability to refill the fuel container in an easy manner and an easy controlled, but not easily avoided, mechanism to prevent the device from being inadvertently ignited, particularly by children who may unintentionally obtain access to the device.